Ubuntu Security Notice USN-1238-2

Ubuntu Security Notice 1238-2 - USN-1238-1 fixed vulnerabilities in Puppet. The upstream patch introduced a regression in Ubuntu 11.04 when executing certain commands. This update fixes the problem. It was discovered that Puppet incorrectly handled the non-default "certdnsnames" option when generating certificates. If this setting was added to puppet.conf, the puppet master's DNS alt names were added to the X.509 Subject Alternative Name field of all certificates, not just the puppet master's certificate. An attacker that has an incorrect agent certificate in his possession can use it to impersonate the puppet master in a man-in-the-middle attack.

It was discovered that Puppet incorrectly handled the non-default "certdnsnames" option when generating certificates. If this setting was added to puppet.conf, the puppet master’s DNS alt names were added to the X.509 Subject Alternative Name field of all certificates, not just the puppet master’s certificate. An attacker that has an incorrect agent certificate in his possession can use it to impersonate the puppet master in a man-in-the-middle attack.

Update instructions:

The problem can be corrected by updating your system to the followingpackage versions:

Ubuntu 11.04: puppet-common 2.6.4-2ubuntu2.6

In general, a standard system update will make all the necessary changes.